Question: Solve for $a$ : $-1 + a = 24$
Add $1$ to both sides: $ \begin{eqnarray} \\ -1 + a &=& 24 \\ \\ {+1} && {+1} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-1 + a} &\hphantom{=}& \hphantom{24} \\ a &=& 24 {+ 1} \\ \end{eqnarray} $ Simplify. $ a = 25$